The present invention is directed to a twin-compartment container or two-compartment container for use in a beverage container whereby two products will remain separate until the moment that the customer wishes to consume the mixture thereof. This ensures that the mixture is fresh and in the ideal condition to drink.
It is a well-known technique to use small capsules or the like for initiating a production of bubbles in a beverage which contains carbon dioxide and optionally nitrogen. Specifically, such capsules are intended to provide a creamy head on freshly poured out beer. Bubbles may be initiated as follows: During the filling process of the beverage container, a drop of liquid nitrogen or the like is deposited in the container before it is rapidly closed. The liquid nitrogen evaporates and, together with the carbon dioxide present, an over-pressure is created in the container, e.g. by the said nitrogen. The capsule inside the container which is fixed to the bottom of the container or close thereto, has at least one opening which is very small. Immediately upon closure of the container, the latter is placed upside down such that the small opening of the capsule comes into communication with the headspace above the beverage in the container. Now, pressure equilibration between the inside of the capsule and the headspace above the beverage occurs. The gas under pressure enters the capsule until the inside pressure and the outside pressure are equal. Subsequently, the container is brought into its xe2x80x9cnormalxe2x80x9d upright position. Due to the surface tension of the beverage, no or only few liquid may enter the capsule. Upon opening the beverage container, the pressure within the container drops immediately to ambient pressure thereby inducing a pressure difference between the inside and the outside of the capsule. This causes release of small bubbles through the small opening(s) which assist in the formation of the desired head of the beverage.
Instead of small orifices, the capsule may be provided with different valve means which respond to the mentioned pressure difference upon opening the beverage container. In such cases, positioning of the container into xe2x80x9cupside downxe2x80x9d is not required; however, production costs are increased. Moreover, these capsules are to be filled with gas and closed under over-pressure.
In WO 91/07326, such a capsule is disclosed. It is in the form of a closed hollow insert (for insertion into a container) having means responsive to opening of the container to provide communication between the inside of the insert and beverage contained in the body of the container upon opening of the container. The orifice in the wall of the capsule is in the lower half of the capsule and is suitably in a lower wall, suitably at or burst disk which, upon subjecting the burst disk to the pressure difference between the inside of the capsule and the atmosphere pressure in the container as or after it is opened, bursts to provide the orifice. The closure means may alternatively comprise a manually openable valve or puncturing device connected to the container closure. Alternatively, the closure means may comprise a pressure responsive valve which, when exposed to the pressure difference between the inside of the capsule and the atmospheric pressure in the container after opening, opens. The valve may suitably consist of a bore terminating in an orifice and a clock on the outside of the capsule which fits inside the b ore and which, when subjected to the pressure difference created on opening the container, is blown out of the bore. Additional embodiments of the valve are also described.
Recently, it has been suggested in PCT/EP 94/02491 to use such known insert as a capsule for receiving a second liquid to be mixed with the beverage liquid immediately before the beverage in the container is poured out or consumed. It is suggested to partly fill the said capsule with the second liquid whereby a second headspace above this liquid is provided. When the beverage container is opened and the pressure in the primary headspace above the beverage liquid in the beverage container drops to atmospheric, the pressure difference between the secondary headspace and atmospheric pressure causes the pressure-sensitive closure to open an orifice in the wall of the capsule, the orifice in the wall of the capsule being in the lower half of the capsule, and the secondary liquid to be ejected from the capsule into the primary liquid.
The said capsule is preferably precharged to a pressure above atmospheric. When this is the case, it may be held under this pressure whilst it is inserted into the container and the entire container and capsule held under this pressure whilst it is filled with a primary liquid. Due to the presence of a valve resisting to the step of pre-pressurizing the interior of the capsule, costs to provide such a capsule are very high.
It is also possible according to the said application to not pre-pressurize the capsule. In this case, there must be communication between the interior of the capsule and the outside thereof inside the beverage container which may cause contamination (e.g. leakage of the second liquid), or there must be a need for physical changes in the capsule to take place, e.g. shrinking, softening or the like. It is obvious that such additional steps and selection of useful materials therefore is also a source for additional costs.
However, because beverage containers are produced in high numbers, it is desired to lower the costs for such capsules.
Accordingly, the present invention provides a container for receiving a flavour for the mixture thereof with a first beverage liquid in a beverage container immediately after opening the beverage container. It is a two-compartment container which does not need to be pre-pressurized before its insertion into the beverage container. One of the two compartments (xe2x80x9cfirst compartmentxe2x80x9d) is intended to be completely filled with the flavour, while the other one (xe2x80x9csecond compartmentxe2x80x9d) is intended to be filled only with gas. The flavour may be a second beverage liquid, a syrup, or may be in a solid state, e.g. a powder or granulate. That compartment which contains gas (second compartment) is in communication with the outside, i.e. the so called primary chamber of the beverage container. This communication is provided by at least one orifice being of any shape provided that the gas flow is restricted sufficiently so that, on one hand, a gas flow slowly equilibrates the pressure difference inside and outside the compartment after closure of the beverage container within a considerable period of time, e.g. in the range of from some seconds to half an hour or one hour, while, on the other hand, upon a sudden pressure decrease in the primary chamber of the beverage container (i.e. after opening it), the gas cannot escape sufficiently fast to equilibrate the pressure decrease in the same magnitude of time as it appears on opening the beverage container (i.e. in the range of about {fraction (1/100)} to {fraction (1/10)} of a second).
There is no communication between the flavour containing, first compartment of the two-compartment container and the primary chamber of the beverage container. This first compartment is completely sealed. Preferably, it is completely filled with the second liquid, powder, granulate or the like.
In one embodiment of the invention, the two-compartment container of the present invention consists of at least two parts, a top part and a base part, at least one of which having side walls extending to the other part, such that upon connecting both parts, the said two compartments are provided. Two different kinds of side walls exist.
The surrounding outer side wall of the two-compartment container at least partly defines the outer wall of the gas containing compartment (second compartment) and is connectable or connected to the opposite base part or top part via closure means. This closure means must be such that it opens or breaks upon the sudden pressure difference which appears as soon as the seal of the beverage container is opened and the container is vented, whereby the over-pressure decreases to ambient pressure. The orifice(s) in the gas containing compartment provided for slow equilibration of pressure is/are restricted such that during the sudden pressure decrease, the gas is not able to exit this orifice(s) in order to equilibrate the pressure. Therefore, the pressure difference upon opening the beverage container fully rests on the said closure means. Because it cannot withstand the force caused by the pressure difference, the closure means opens or breaks.
The inner side wall which separates the two different compartments inside the two-compartment container is a continuous wall which fits tightly to the opposite part (base part or top part), as long as both parts of the two-compartment container are connected. Due to this, the two compartments are completely separated without the possibility that gas or other fluid escapes from its compartment and introduces into the other compartment. However, there is no closure means or only a rather weak one between the said inner side wall and the respective opposite part of the two-compartment container so that upon opening or rupture of the connection between the outer side wall and the opposite base part or top part, the inner side wall does no longer tightly fit to the opposite part of the said container but is released therefrom. Consequently, the flavour can freely escape from its compartment.
The at least one small orifice for merely slow equilibration of pressure between the inside of the gas containing compartment of the two-compartment container and the outside thereof may be one upper restricted orifice provided in an upper part of the outer wall or in the top thereof. This restricted orifice is of such a size that, being in communication with the liquid in the container, no or only few liquid may enter. This is due to the xe2x80x9cbubble point effectxe2x80x9d caused by surface tension forces. However, the restricted orifice allows slow equilibration of pressure between the inside and outside, as detailed above. xe2x80x9cSlow equilibrationxe2x80x9d means equilibration during a time period of from about a few seconds up to half an hour or one hour: It is assumed that a drop of liquid nitrogen added immediately before the beverage container is sealed will evaporate during about 15 seconds. As an example, it may take about the same time to equilibrate about 80% of the pressure difference if the restricted orifice is in communication with the gaseous headspace of the beverage container (e.g. in upside down position of the beverage container if the two-compartment container is sealed to the bottom thereof. Full equilibration will normally almost or fully be completed after thexe2x80x94optionalxe2x80x94pasteurization has been finished (e.g. within 0.5-1 hour).
The restricted orifice may be a small hole extending through the wall or top of the respective part of the two-compartment container. Alternatively, it may consist e.g. of the following elements: around the orifice, the top part surface is restricted forming an almost cylindrical recess from whose base the frusto-conically tapered portion extends upwards towards or reaching height of the top part surface. The restricted orifice is provided at the top of the said frustoconically tapered part. In still another exemplary embodiment, the inside of the top part is provided with a small cylindrical body made of the same material. Extending through this cylinder and through the top part, a small hole extends providing the orifice at the surface of the top part.
The closure means of the surrounding outer wall may e.g. be a snap-fit connection, an interference fit connection or a membrane. The snap-fit must be tightly fitting; however, it must be sufficiently weak that the forces to be overcome when the snap-fit is opened (i.e. friction forces and shape changing forces) are less than the forces caused by the pressure difference upon opening the beverage container. Ideally, the two-compartment container is made from a material which is sufficiently flexible to provide small shape changing forces, e.g. a polyalkylene, preferably polypropylene. This material may advantageously be used for preparation of the complete two-compartment container because it is hydrophobic, providing the desired surface tension characteristics. In a specific embodiment, the surface of those parts of the two-compartment container providing the snap-fit are coated with a friction-reducing agent or lubricant. If the closure means is an interference fit, the base part of the two-compartment container comprises a lower part of the outer side wall (i.e. integrally or inseparably mounted or connected), and the top part thereof likely comprises an upper part of the outer side wall. The fit is provided by overlapping upper and lower side wall parts. The forces to open the interference fit between both side wall parts must be sufficiently weak and less than the forces caused by the aforementioned pressure difference upon opening the beverage container. The seal of the interference fit may either be provided only by the area of overlapping walls or additionally by a gasket or packing ring. In another embodiment, the closure means is a thin membrane. This membrane may e.g. constitute the top part or the base part of the two-compartment container which may be weakly sealed to the respective outer wall ends. It must be sufficiently strong such that in case the seal to the outer wall ends bursts or breaks due to the sudden pressure difference, the fitting with the inner wall is also opened.
The inner wall which tightly fits to the opposite part of the two-compartment container may be without any closure means. Upon opening the connection between the outer side wall and the opposite part, liquid or powder or the like can therefore freely escape from its compartment. In another embodiment of the invention, closure means are provided in order to form the tight fitting. However, these closure means must be weak and must open together with the disconnection of the closure means of the outer side wall. For example, it may be an interference fit the overlapping distance of which is lower than that of an interference fit between parts of the surrounding outer wall. If the forces of the pressure difference upon opening the beverage container urge the interference fit between the outer wall parts to open, the lower length of interference of the inner wall necessarily provides opening thereof.
In a preferred embodiment, the two-compartment container consists of the top part comprising the top, the inner wall and the surrounding outer wall. The lower ends of the walls fit with the base part, and the surrounding outer wall thereof comprises means for a snap-fit, as well as the bottom part of the two-compartment container. In order to fill such a container, it is brought in an upside down position.
In a further preferred embodiment, the two-compartment container has a substantially cylindrical form, the bottom having the shape of a circular plate (or dome) extending outwardly therefrom. The outer wall and the bottom (or, in another embodiment, the top) are provided with closure means, and the closure extends roundabout the bottom of the two-compartment container. The first compartment of the two-compartment container which is intended to be filled with a flavour may be inside the second compartment. In this case, an inner wall (which may consist of four walls arranged in a rectangular form or the like, however, has preferably a circular shape) is provided. Thus, the inner wall separating a first and a second compartment does not extend to the outer wall so that the second compartment intended to receive the gas completely surrounds the first compartment. This latter embodiment is preferred, and specifically, an embodiment comprising circular inner and outer walls is preferred. Such containers may be advantageously prepared with low costs. There is no need that the outer or second compartment has the same height as the inner compartment. It may be favorable that it is lower. In this case, the tops of the two compartments are separated by a step or shoulder.